The number of characters in one electronic mail transmission is limited, due to handling limitations of a radio transmission or handling limitations of a portable phone display and so forth. Without any change, this causes great inconvenience to a portable phone user who cannot receive and transmit an electronic mail beyond a certain limitation, e.g., 250 characters.
Solutions to this problem are available. The technique of Japanese Patent Laid-Open Publication No. 9-51353 can be exemplified. According to this Japanese Patent Laid-Open Publication No. 9-51353, a mail server receives an electronic mail addressed to a certain portable phone as a first step and automatically divides the electronic mail into electronic mail sections with a certain length, if the character number exceeds handling limitations. The electronic mail section(s) divided in this way will be called “mail section(s)” hereinafter. Then the mail server puts a section number (i/m) on each section and transmits the mail sections to an addressee's portable phone. Here “m” is the total number of the mail sections and “i” is a certain section number assigned to each section of the mail sections. Upon receipt of these sections the addressee's portable phone sorts the mail sections by referring to the section number. Then the portable phone displays the mail sections one by one in numerical order in accordance with user's page turnover operation. Through this operation the mail sections are displayed as if they were a single non-divided electronic mail.
There are, however, different processing types other than the display processing by user's page turnover operation for mail sections received through a portable phone. For example, received mail sections can be deleted from portable phone's memory, returned to the sender, or transferred to another user's portable phones.
However, operations such as deletion, return and transfer of the above-mentioned mail sections are inconvenient for users. The problem originates from the difficulty of memorizing one electronic mail as plural mail sections.